diff --git a/pom.xml b/pom.xml
index b3b1536..e3e64d2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -70,7 +70,7 @@
         <dependency>
             <groupId>commons-cli</groupId>
             <artifactId>commons-cli</artifactId>
-            <version>1.4</version>
+            <version>1.6.0</version>
         </dependency>
         <dependency>
             <groupId>javax.xml.bind</groupId>
@@ -80,12 +80,24 @@
         <dependency>
             <groupId>org.javassist</groupId>
             <artifactId>javassist</artifactId>
-            <version>3.21.0-GA</version>
+            <version>3.30.2-GA</version>
         </dependency>
         <dependency>
             <groupId>com.sun.activation</groupId>
             <artifactId>javax.activation</artifactId>
             <version>1.2.0</version>
         </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>commons-codec</groupId>
+            <artifactId>commons-codec</artifactId>
+            <version>1.15</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 </project>
\ No newline at end of file
diff --git a/src/main/java/io/zhile/crack/atlassian/agent/KeyTransformer.java b/src/main/java/io/zhile/crack/atlassian/agent/KeyTransformer.java
index 1626542..e0d4fcc 100644
--- a/src/main/java/io/zhile/crack/atlassian/agent/KeyTransformer.java
+++ b/src/main/java/io/zhile/crack/atlassian/agent/KeyTransformer.java
@@ -1,13 +1,14 @@
 package io.zhile.crack.atlassian.agent;
+
 import javassist.*;
 
-import java.io.File;
 import java.lang.instrument.ClassFileTransformer;
 import java.lang.instrument.IllegalClassFormatException;
 import java.security.ProtectionDomain;
 import java.util.Arrays;
-import java.util.Map;
-import java.util.Objects;
+import java.io.ByteArrayInputStream; // Import for the inserted code to resolve
+import java.io.DataInputStream; // Import for the inserted code to resolve
+import java.nio.charset.StandardCharsets; // Import for the inserted code to resolve
 
 /**
  * @author pengzhile
@@ -29,7 +30,7 @@ public byte[] transform(ClassLoader loader, String className, Class<?> classBein
         if (className.equals(CN_KEY_SPEC)) {
             return handleKeySpec();
         } else if (className.equals(LICENSE_DECODER_PATH)) {
-            return handleLicenseDecoder();
+            return handleLicenseDecoder(loader);
         }
 
         return classfileBuffer;
@@ -74,24 +75,16 @@ private byte[] handleKeySpec() throws IllegalClassFormatException {
      * @return 修改过的类的字节码
      * @throws IllegalClassFormatException 当某些地方出问题了就会抛出这个异常
      */
-    private byte[] handleLicenseDecoder() throws IllegalClassFormatException {
+    private byte[] handleLicenseDecoder(ClassLoader loader) throws IllegalClassFormatException {
         try {
-            // 我不知道怎么从 com.atlassian.bitbucket.internal.launcher.BitbucketServerLauncher 读取这个路径，所以我直接 HARD CODE
-            // Forgive me pls...
-
-            Map<String, String> osEnv = System.getenv();
-            String binDir = osEnv.get("BIN_DIR");
-            String path = binDir.replace("bin", "app/WEB-INF/lib");
-            File libs = new File(path);
-            ClassPool cp = ClassPool.getDefault();
+            // Use a ClassPool that defaults to the system classpath (includes JDK classes)
+            ClassPool cp = new ClassPool(true);
 
-            Arrays.stream(Objects.requireNonNull(libs.listFiles())).map(File::getAbsolutePath).forEach((it) -> {
-                try {
-                    cp.insertClassPath(it);
-                } catch (Exception e) {
-                    e.printStackTrace();
-                }
-            });
+            // Append the classpath of the loader that loaded the target class.
+            // This ensures we can resolve classes available to the target class (e.g. libraries in WEB-INF/lib).
+            if (loader != null) {
+                cp.appendClassPath(new LoaderClassPath(loader));
+            }
 
             cp.importPackage("com.atlassian.extras.common.LicenseException");
             cp.importPackage("com.atlassian.extras.common.org.springframework.util.DefaultPropertiesPersister");
@@ -120,7 +113,7 @@ private byte[] handleLicenseDecoder() throws IllegalClassFormatException {
             cp.importPackage("java.util.zip.InflaterInputStream");
             cp.importPackage("org.apache.commons.codec.binary.Base64");
 
-            CtClass target = cp.getCtClass(LICENSE_DECODER_CLASS);
+            CtClass target = cp.get(LICENSE_DECODER_CLASS);
             CtMethod verifyLicenseHash = target.getDeclaredMethod("verifyLicenseHash");
             verifyLicenseHash.setBody("{System.out.println(\"atlassian-agent: skip license hash check\");}");
             CtMethod checkAndGetLicenseText = target.getDeclaredMethod("checkAndGetLicenseText");
@@ -144,4 +137,4 @@ private byte[] handleLicenseDecoder() throws IllegalClassFormatException {
         }
     }
 
-}
\ No newline at end of file
+}
diff --git a/src/test/java/io/zhile/crack/atlassian/agent/KeyTransformerTest.java b/src/test/java/io/zhile/crack/atlassian/agent/KeyTransformerTest.java
new file mode 100644
index 0000000..1ba9ec8
--- /dev/null
+++ b/src/test/java/io/zhile/crack/atlassian/agent/KeyTransformerTest.java
@@ -0,0 +1,104 @@
+package io.zhile.crack.atlassian.agent;
+
+import org.junit.Test;
+import java.io.File;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Comparator;
+import static org.junit.Assert.*;
+
+public class KeyTransformerTest {
+
+    @Test
+    public void testHandleLicenseDecoder() throws Exception {
+        // 1. Setup temporary directory for dummy classes
+        Path tempPath = Files.createTempDirectory("agent_test_classes");
+        File tempDir = tempPath.toFile();
+        tempDir.deleteOnExit();
+
+        try {
+            // 2. Create Version2LicenseDecoder dummy class
+            File packageDir = new File(tempDir, "com/atlassian/extras/decoder/v2");
+            assertTrue(packageDir.mkdirs());
+
+            File sourceFile = new File(packageDir, "Version2LicenseDecoder.java");
+            Files.write(sourceFile.toPath(),
+                ("package com.atlassian.extras.decoder.v2;\n" +
+                 "public class Version2LicenseDecoder {\n" +
+                 "    public void verifyLicenseHash() {}\n" +
+                 "    public String checkAndGetLicenseText(String s) { return \"\"; }\n" +
+                 "}\n").getBytes());
+
+            runJavac(sourceFile);
+
+            // 3. Create LicenseException dummy class
+            File commonDir = new File(tempDir, "com/atlassian/extras/common");
+            assertTrue(commonDir.mkdirs());
+
+            File leSourceFile = new File(commonDir, "LicenseException.java");
+            Files.write(leSourceFile.toPath(),
+                ("package com.atlassian.extras.common;\n" +
+                 "public class LicenseException extends RuntimeException {\n" +
+                 "    public LicenseException(Throwable t) { super(t); }\n" +
+                 "}\n").getBytes());
+
+            runJavac(leSourceFile);
+
+            // 4. Create custom ClassLoader
+            URL[] urls = new URL[] { tempDir.toURI().toURL() };
+            // Use the current test classloader as parent so it can find commons-codec (which is in test dependencies)
+            ClassLoader parentLoader = getClass().getClassLoader();
+            URLClassLoader appLoader = new URLClassLoader(urls, parentLoader);
+
+            // 5. Instantiate Transformer
+            KeyTransformer transformer = new KeyTransformer();
+            String className = "com/atlassian/extras/decoder/v2/Version2LicenseDecoder";
+
+            // 6. Transform
+            byte[] dummyBytes = new byte[0];
+            byte[] result = transformer.transform(appLoader, className, null, null, dummyBytes);
+
+            assertNotNull("Transformation result should not be null", result);
+            assertTrue("Transformation result should not be empty", result.length > 0);
+
+        } finally {
+            // Cleanup
+            Files.walk(tempPath)
+                .sorted(Comparator.reverseOrder())
+                .map(Path::toFile)
+                .forEach(File::delete);
+        }
+    }
+
+    @Test
+    public void testHandleKeySpec() throws Exception {
+        // This test verifies that handleKeySpec returns transformed bytecode.
+        // It relies on java.security.spec.EncodedKeySpec being available in the system (it is).
+        // And javassist finding it (via ClassPool.getDefault()).
+
+        KeyTransformer transformer = new KeyTransformer();
+        String className = "java/security/spec/EncodedKeySpec";
+
+        // We pass empty byte array. The transformer uses ClassPool to read the class.
+        byte[] dummyBytes = new byte[0];
+
+        // Note: transform takes "className" with slashes
+        byte[] result = transformer.transform(ClassLoader.getSystemClassLoader(), className, null, null, dummyBytes);
+
+        assertNotNull("Transformation result should not be null for EncodedKeySpec", result);
+        assertTrue("Transformation result should not be empty for EncodedKeySpec", result.length > 0);
+    }
+
+    private void runJavac(File sourceFile) throws Exception {
+        Process p = Runtime.getRuntime().exec("javac " + sourceFile.getAbsolutePath());
+        p.waitFor();
+        if (p.exitValue() != 0) {
+            // Read stderr
+            java.util.Scanner s = new java.util.Scanner(p.getErrorStream()).useDelimiter("\\A");
+            String err = s.hasNext() ? s.next() : "";
+            throw new RuntimeException("Failed to compile " + sourceFile.getName() + ": " + err);
+        }
+    }
+}
diff --git a/src/test/java/io/zhile/crack/atlassian/agent/ManualAgentVerify.java b/src/test/java/io/zhile/crack/atlassian/agent/ManualAgentVerify.java
new file mode 100644
index 0000000..093c074
--- /dev/null
+++ b/src/test/java/io/zhile/crack/atlassian/agent/ManualAgentVerify.java
@@ -0,0 +1,29 @@
+package io.zhile.crack.atlassian.agent;
+
+import java.security.spec.EncodedKeySpec;
+import java.security.spec.X509EncodedKeySpec;
+import java.util.Base64;
+
+/**
+ * Manual verification script.
+ * Usage:
+ * java -javaagent:target/atlassian-agent.jar -cp target/test-classes io.zhile.crack.atlassian.agent.ManualAgentVerify
+ */
+public class ManualAgentVerify {
+    public static void main(String[] args) {
+        System.out.println("Starting ManualAgentVerify...");
+
+        // This key matches the one hardcoded in KeyTransformer to trigger the "agent working" message
+        String keyBase64 = "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";
+        byte[] key = Base64.getDecoder().decode(keyBase64);
+
+        try {
+            // X509EncodedKeySpec extends EncodedKeySpec.
+            // Creating this instance should trigger the agent transformation if attached.
+            EncodedKeySpec spec = new X509EncodedKeySpec(key);
+            System.out.println("Created EncodedKeySpec instance.");
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+}